Russelectric's medium-voltage (5-15 kV) circuit breaker-type transfer switches and bypass/isolation switches are UL tested, listed and labeled under UL 1008A, making them suitable for use in legally required emergency power systems. These switches transfer electrical loads between normal and emergency power sources through the carefully controlled opening and closing of circuit breakers and may be configured for open- or closed-transition transfer. All switch functions are controlled by Russelectric's RPTCS programmable microprocessor-based control system. All medium-voltage circuit breaker-type switches meet or exceed stringent IEEE, NEMA and ANSI standards.

For either the open- or closed-transition configuration, if the primary source is lost, the control initiates an open-transition transfer to the emergency source by tripping the primary source breaker and closing the emergency source breaker. When open-transition retransfer is selected, the switch verifies the primary source has returned, opens the emergency source breaker, then closes the primary source breaker. When closed-transition retransfer is selected, the switch performs a synch check to ensure the primary source is in synch with the emergency source, parallels the two sources by closing the primary source breaker, then opens the emergency source breaker.

Russelectric allows offers medium-voltage circuit breaker-type bypass/isolation switches that provide all the functions of an automatic transfer switch plus the ability to bypass power from live source to load in the event the transfer switch becomes disabled. In addition, they are designed to allow isolation and de-energization of the automatic transfer breakers for maintenance, testing and repair. The operator can choose between load-break bypass and no-load-break bypass by means of a selector switch on the front of the control cubicle.

Russel Electric |